Boat hull construction



G. W. SMITH, JR

BOAT HULL CONSTRUCTION ocr. 16, 1934.

2 Sheets-Sheet l Filed Feb. 25, 1935 l/ 4/4 w45 3 2 w ,J7 /5 A d d 6 3824 3 3 ct. 16, 1934. G. W. sMlTH, JR

BOAT HULL CONSTRUCTION Filed Feb. 25, 1933 2 Sheets-Sheet 2 maentor 650/865 nl. SVV/77%, .7B

Gttornegs z55 st rakesy to the ribs;`-

Patented Oct. 16, 14934 'BOAT HuLLooNsTRUoTIoN Y George W. Smith, Jr., Cleveland, Ohio Application'February 23, 1933, Serial No. 657,949

4 Claims.

This invention relates to improvements in boat hull construction and particularly to the type `of hull construction used in small Water craft.

kThe conventional hull construction as used in Y; small boats usually includes a frame' having transversely disposed bent ribs to which are secured strakes. The planks forming the strakes are usually fastened to the ribs by brass or galvanized inner screws or copper rivets or the like.

When screws are used they are disposed in counterbores in the planks and screwed into the wooden ribs. The bore is then plugged by wooden plugs which are smoothed off flush with the surface. When copper rivets are used they usually are disposed in counterbores in the planks and extend through and are riveted at the inner side of the ribs. The seams between the strakes are then caulked with cotton, oakum or the like together with a seam filling composition. The

"2Q surface of the hull is then usually painted or Varnished upon the outside.

This type of construction necessitates theuse of heavy planks in order that they may be counterbored for the recesses. The counterboring and plugging of the bores takes considerable time and labor. It is also necessary to-prcvide butt blocks between the ribs where the planks forming thestrakes abutt. The wood coming in contact with the water, in spite-of the painting usually becomes water soakedrand heavy.l Wood construction is also subject to the attacks of various types of marine borers whose activities also weaken the planks. The wetting and drying of the planks also tends to force out the ca ulking between the strakes, making frequent caulkingA necessary. y

The present invention is designed to eliminate the foregoing disadvantages due to wooden con-V struction, permitting lighter construction and furnishing protection for the woodagainst Water and marine borers. v t *l The invention relates broadly in providing metallic coverings for the planks with expansion joints at each edge of the planks and also per.- mits' the seams between the planks to be sealed against fluid pressure. In order that myinvention may be better understood reference may be had to the accompanying drawings and the specication explaining the drawings wherein an embodiment of the invention is shown.

In the drawings: n

Figure 1 is a fragmentary transverse sectional View of a boat hull of the carvel built construction showing the method of attaching the Figure 2 is a fragmentary horizontal sectional view taken through the side of a boat showing the abutting lplanks which form the strakes;

Figure 3 is a plan view of a metal plank used to cover the planks and showing in dotted lines @e Where the same is adapted to be bent; f

Figure 4 `is a transverse section taken on the line 4 4 of Figure 3 and showing in dotted lines the final position taken by the metal after application; t

Figure 5.is ya fragmentary vertical medial sectional view of a boat hull structure of clinker builtlap strake construction showing the metal clad planks which form the strakes of the boat; andr vFigure 6 is an enlarged vertical sectional View showing the joint between the two strakes.

Referring now particularly to the drawings through which like parts are designated by like reference characters.

The-boat may comprise the usual frame work having a plurality of transversely disposed ribs or frames such as 2. The strakes are formed of longitudinally extending planks 3 and each plank is provided with double beveled edges 4 and 5 on both the sides and ends. The angle at whichthe edges 5 are. beveled may be less than that for the-edges 4. The planks are secured to the ribs by screws 6. It is not necessary to counterbore the holes in the planks for the screws 6fas the heads of the screws may extend flush with the surface of the planks. The planks are secured to the framework of the hull so posifv tioned that a very slight gap is provided between the planks and whenrso secured there are seams or crevices between the planks which increase in breadth at the surfaces, the seams 8 opening toward theoutside being narrower than the seams 9 4which open 4toward the inside.

After the planks are secured to the ribs, I cover the samewith sheet metal of substantially the formation best shown in Figures 3 and 4, the sheets may be provided with a crown as best shown in Figure 4 which is adapted to be placed with the convex side against the outer surface of the plank. `The sheet is notched at 10 on the corners and adapted to be folded along the dotted lines 11 toform a substantially rectangular shell. The corners 10, where the sheet comes togethenwhen folded Amay be soldered or welded prior to application. The shells are then placed over the planks. The crown formed in the shell is adapted to hold the metal tightly against the surface of the planks. The edges are then crimped over the inner bevel as at 14. In this the planks. Y ered on ve sides and a portion of the sixth side,

manner each plank has its surface which is the outside of the hull and surfaces adjacent to the other planks covered by metal.

It may be advisable to merely form the one longitudinal edge and the ends of the metal plank and then place the metal over the plank and bend the last longitudinal edge into place after which the edges 14 may be crimped over the inner bevel.

When the planksare all coveredtheconstruction provides a plurality of metal channels between all the planks conforming to the seams 8 and 9. soldered at 20. in the inner surface.

This provides a fluid-tight seal After the seams are thus sealed, the outer crevices are packed with me-V tallic wool 21 such as lead which is Worked into the crevices to provide an expansion joint and a smooth exterior surface. j

It may be advisable to reverse the seam sealing operation and caulk the outer seam first and solder the inner seam last.

The metal used to cover the planks may be any one of several kinds such as copper-nickel sheets called Monel metal; stainless steel; galvanized iron; Terne plate or the like. It is not my intention to limit the invention to any particular kind of sheet metal. v

The hull constructed as described is economical as the same thickness of planking may be used throughout. No dies are necessary inasmuch as the crown may be rolled. The construction is also lighter because butt blocks are j eliminated and the planking used may also be thinner, it being unnecessary to counterbore the screw holes. The constant servicing necessary in all wood construction is also eliminated as the metal is unaffected by Wood borers or the like and the usual organic material such as cotton or oakuin caulking is eliminated.

The metal covers need only be used below the water line and slightly above the water line, although of course all the wood planks may be so covered should it be desired.

In Figures 5 and 6 I have shown another form of metal clad planks used in clinker built or lap strake construction wherein the rib 30 of the hull has secured to it the planks 31 in lapping relation. In this structure the planks are of the substantially rectangular cross section and are secured to the ribs by bolts or rivets 32 which extend through the plank through one edge of metal sheathing 33 and through' the plank which is lapped and the rib. The metal sheet is the first stage of application extends in prolongation of the inner 'surfaces of the plank as shown by the dotted line at 34' being held securely between the lapping edges of adjacent planks. The head of the bolt or rivet is flush with the surface of the plank. After the plank has been secured at the lowermost portion the sheet is bent upward around the plank to cover the rivet and presents an entirely metal clad surface to the The upper edge of the metal sheet is held in place by the next succeeding plank which is applied being attached at'its lower end in overlapping relation with the previously attaehed plank together with the metal sheet for This permits the planks to be covthe metal sheet being of similar form to Vthat of Figure 3, the crown in the blank vcausing the metal to adhere closely to the surface of the plank. After the structure is completed the inner seams may be soldered as at 38 in Figure 6.

The inner channels or seams are thenA By thus forming the structure I provide a metal clad boat where the wood does not come into contact with the water and wherein considerable saving in the weight of the structure is obtained. An inferior grade of Wood may also be used if desired, knots having no effect upon the planks because they do not come in contact with the Water. It Will be noted that the soldered joint is disposed contiguous the bevelled edge portion of. the planks so .that a fulcrum is provided about which the planks are free to move when the planking is shrunk, as for instance when the boat hull is in dry dock or when the material is swollen due to the presence ofl moisture. By vrture of this construction the planking material is free to move within and independent of the encasing metal plates, the soldered seam preventing leakage and the bevelled edge portion of the plank providing a substantially line contact or hinge to permit expansion when the planking is swollen.

Having thus described my invention I am aware that numerous and extensive departures may be made therefrom Without departing from the spirit and scope of the appended claims.

I claim:

1. In a hull construction including ribs for the hull, planks secured to the ribs and so formed whereby double wedge-shaped openings are formed, a covering for said planks for protecting the same against water and including a metallic sheet adapted to closely engage a plank and to be folded aboutthe plank on at least five sides and conforming to the double wedge shaped conformation of the openings at the adjoining edges of the planks, said openings including one opening toward the inside of the hull and one opening toward the outside with the apexes of the openings adjoining, said inner openings adapted to be soldered to seal the adjacent members to each other, said outer openings adapted to be caulked to seal the outer opening and prevent skin friction with the water and to permit expansion and contraction of said metal.

2. In a boat hull construction including ribs for the hull, planks secured lto the ribs so as to provide openings therebetween, means to shield the planks including metallic sheets of inwardly bowed formation and adapted to be 125 disposed about the planks so that the bowed portion causes the sheet to adhere closely to the exterior surface of each plank, the edges of said sheet being folded about the planks, said planks having their edges so formed that when the sheets are folded about the planks metallic lined grooves are provided by the metallic sheets on the inside and outside meeting edges of the planks, said inner grooves adapted to be soldered to provide a fluid seal, said outer groove 135 adapted to be caulked to prevent skin friction.

'3. In a boat hull construction including ribs, sheathing secured to the ribs, each plank of said sheathing having the edge beveled from l, a mid point toward the inner and outer surface 140 of the hull, means toY cover the individual planks comprising a metal sheet preformed to provide a crown adapted to contact with the outer surface of the plank, said sheet being folded about the beveled edges of said planks, said metallic 145 members forming grooves around each plank on the inside and on the outside of the hull, said inner grooves adapted to be soldered to provide a fluid tight seal between the metal coverings and said outer grooves adapted to be caulked 150 with .lead wool flush with the surface of the metal sheets.

4. In a boat hull construction including ribs, sheathing secured to the ribs, each plank of said sheathing having a bevelled edge portion, metal coverings for said planks comprising metallic sheets formed to encase the ends, side edge and outer face of said planks, the inner edges 

